Airtight container is a very common article for daily use, always used for cutting off ambient air from articles such as foods, biscuits, batteries etc. to keep them from moisture. Usually, a rotary airtight container has a body, a cover threadly connected with the body, an air grommet washer provided on the opening of the body to realize the isolation of air from the inside of the container. In order to work well, this kind of airtight container needs the cover to be tightly engaged with the body, but it is not easy to operate, and if a user wants to take out the articles from the container, it is also very hard to open the cover.